Resident Evil Cheats

After beating the game on normal difficulty in 5 hours or less with either Chris or Jill, you will have access to the Samurai Edge during the next game.
NOTE: This is NOT a sword.

This is a step by step guide to getting this glitch to work. Follow these instructions or it will fail.
Requirements: You must have the grenade launcher and two types of ammo (e.g., Grenade Rounds, Incendiary Rounds)
1) Put all items in item box
2) Put Grenade Launcher in upper-left item slot
3) Put Incendiary Rounds in upper-right item slot
4) Close box
5) Open inventory
6) Equip Grenade Launcher
7) Open box
8) Select Incendiary Rounds from inventory
9) Press ''A'' twice
10) Move cursor to Incendiary Rounds inside box
11) Press ''A'' twice
The amount of Incendiary Rounds in the Grenade Launcher will now increase. The number value will be graphically glitched. Close the box and open inventory to fix that. I assume the value exceeds the possible amount, so the game automatically reduces the rounds to 240 to prevent data corruption. Enjoy.
This also works for other types of grenade ammo... But why you'd want anything other than Incendiary Rounds is beyond me.
NOTE: This code does not work in the PAL version of the game.

To unlock this mode beat Real Survival mode once.

Complete the game with Jill once and save the game.A few things will change.
1-The main menu will have a different background.
2-If you select the option'Once Again(with your save data loaded)'you will be given a choice of difficulties to begin the next game with-Easy,Normal and Hard
3-You will receive a key that enables you a costume change(in this case Jill's costume)

Complete the game as both Chris and Jill one time to unlock the ''One Dangerous Zombie'' option. A special zombie will continue to follow you around during the first part of the game. Shooting this zombie will end the game, so you must avoid it during game play.

Beat the game on normal or hard difficulty on the Once Again mode

To get the Rocket Launcher, beat the game in under 3 hours on Normal or Hard mode.

Near the end of the game in the Laboratory, you will reach a computer that you have to enter passwords into in order to progress through the game. If you enter the password "MOLE" from the original game, you will actually hear Tofu from Resident Evil 2 on the computer screen. Strangely, this only works on Easy Mode for some reason.

Beat Invisible Mode in 5:00:00 to open up a message from the director and a slide show of unused costume designs.

complete the game on any charactare under 5 hours

Use th grenade Launcher Trick on the "Flame Rounds". When you face a zombie, simply usea "Flame Round" and they will automatically 'burn'...(Most of the time). If they do not burn,, simply aim the G. Launcher down and fire away...

First get the 22. derringer magnum from the 001 room and save it for
the battle with Tyrant. One shot kills anything including zombies ,
hounds , hunters and so forth.

Cerebreus: If in groups, use the shotgun and take them all out at one time.
Crimsom Heads: Use the same tactics as zombies, except if they charge at you, duck in a door.
Hunter: One acid shell to the face. Wait until they are right on you and fire.
Sharks, Snakes, Birds, Bees: Ignore them.
Spiders: Use six shots of the pistol.
Zombie: Use the magnum for an 80% chance of deception. Otherwise, use the pistol or shotgun.

If you beat the game in normal modein under 5-hours you will start with the samuri edge barry version gun in your inventory when you play again by choosing play again when you beat the game.

Follow these instructions.

1. Have one set of grenade shells in the first item space in your inventory. Have the Grenade Launcher in the second space.

2. Leave the Item Box and equip your Grenade Launcher. Open the Item Box.

3. Go left into the FIRST Item Box space and hit A twice. Hit it twice more.

NOW you should have around 700 Grenade Shells!!

You must have the grenade launcher and two types of ammo (e.g., Grenade Rounds, Incendiary Rounds). Put all items in item box. Put the Grenade Launcher in upper-left item slot. Put Incendiary Rounds in upper-right item slot. Close box. Open inventory. Equip Grenade Launcher. Open box. Select Incendiary Rounds from inventory. Press 'A' twice. Move cursor to Incendiary Rounds inside box . Press 'A' twice.

The amount of Incendiary Rounds in the Grenade Launcher will now increase. The number value will be graphically glitched. Close the box and open inventory to fix that, and enjoy the tons of ammo.

After beating the game on normal difficulty in 5 hours or less with either Chris or Jill, you will have access to the Samurai Edge during the next game.
NOTE: This is NOT a sword.
Source: IGN